1. Technical Field
The present disclosure relates to current regulators; in particular, to a linear current regulator.
2. Description of Related Art
Due to the energy efficiency and energy saving requirements, LED is broadly used in many fields. For instance, electric products, household appliance, cars, traffic lights, and panels which using point light source or surface light source have already become the LED application market. The function of controlling the output brightness of LED is commonly configured to the driving circuit, no matter LED is driven by boost, buck, boost/buck or linearly regulating voltage circuit. Currently, the main controlling methods of LED brightness are digital dimming and analog dimming method.
The digital dimming makes the driving current switch between a zero to a predetermine value. The PWM (pulse with modulation) is a very common method utilized to set circle and duty cycles. However, the issues of electromagnetic compatibility (EMC) and electromagnetic interference (EMI) always occur to cause the potential frequency problem.
Since the output current variation of the LED driver is proportional to the brightness thereof, the analog dimming which linearly regulates LED is easily implemented. Therefore, it's an important topic in this technical filed to find a high linear current regulator for regulating the brightness of LED.